This invention relates generally to pressure protection of high vacuum and ultra-high vacuum containment vessels, and more particularly to a cartridge-style rupture disc for installation between a mating pair of CF type metal seal flanges.
Burst discs are commonly used in high vacuum (HV) and ultra-high vacuum (UHV) systems as a means of protecting a vacuum vessel or chamber against accidental over-pressurization. They are designed to burst or rupture at a predetermined and calibrated relief pressure when the pressure inside the protected vacuum vessel exceeds the specified relief pressure. Burst discs are one-time use safety devices which must be discarded and replaced after use (failure).
The conventional method for incorporating a burst disc in a HV or UHV system is to provide a burst disc mounted in a fixture incorporating an industry standard ConFlat® (CF) type metal seal flange which allows connection to a CF flange provided on the containment vessel. Once the burst disc is ruptured the entire assembly, including the CF metal seal flange, must be scrapped as it is no longer serviceable even though the metal seal flange itself remains undamaged. Advantages would be realized by a burst disc assembly that could be installed in a conventional CF flange interface in a manner that prevented the leakage of gas at the molecular level necessary for HV and UHV applications while minimizing the material to be scrapped upon rupture of the disc. Additional advantages would be realized by a burst disc assembly that could be easily installed within existing containment vessel relief piping without the need to modify the piping or connections.